EKGs
3 steps
Rate
Normal: 60-100
Rhythm
Axis
Left axis deviation: more negative (down) deflection in the inferior leads (II, III, aVF) and a positive deflection (up) in the left lateral leads (I, aVL).
Right axis deviation: more positive (up) deflection in the inferior leads (II, III, aVF) and a more negative (down) deflection in the left lateral leads (I, aVL).
A-Fib comes from pulmonary vein irritation, leading to disorganized electrical signals in the atria, which can result in an irregular and often rapid heart rate.
If amplitude is really high up, it's because of LV hypertrophy, which leads to increased electrical activity and larger voltage changes recorded on the EKG. This can be observed as tall R waves in the left lateral leads (I, aVL) and can be indicative of underlying heart conditions.
Symmetric T-wave depression is likely present in cases of ischemia or left ventricular strain, indicating potential issues with coronary artery health or ventricular overload.
Asymmetric T-wave depression is due to abnormalities in the repolarization process, often associated with conditions such as myocardial infarction or left bundle branch block, and may suggest a more localized area of myocardial damage.
QTc > 500 is a red flag for potentially developing TdP (Torsades de Pointes), a dangerous arrhythmia that can occur in response to prolonged QT intervals, often exacerbated by electrolyte imbalances or certain medications.
PVCs and bradycardia also leads to TdP , particularly in patients with underlying heart conditions, and should be closely monitored to prevent adverse outcomes.
Synchronized cardioversion is for A-Fib if hemodynamically unstable, but if not synchronized properly, that will cause TdP and other serious complications. It is crucial to ensure that the defibrillator is set correctly and that the timing of the shock coincides with the R wave to effectively convert the arrhythmia without inducing further issues.
In first degree heart block, P-R interval ≥ 260 ms
If P wave goes down in V1, it's left atrial enlargement ;if it goes up, it indicates right atrial enlargement.
Additionally, the presence of a wide QRS complex may suggest a bundle branch block, which should also be evaluated in conjunction with the overall clinical picture.
QS complex and Q wave = old myocardial infarction, particularly if accompanied by ST segment elevation or depression, indicating significant underlying ischemia.
Diffuse ST elevation with no depression = pericarditis, often associated with chest pain that worsens when lying down and improves when sitting up.
T wave inversion in the lateral leads can indicate ischemia or prior myocardial infarction, while upright T waves usually suggest normal myocardial repolarization.
Finally, the QT interval should be measured to assess for potential risk of arrhythmias, with prolonged intervals being a concern for torsades de pointes.
Shortened QT interval may indicate hypercalcemia or digoxin toxicity, which can lead to increased risk of ventricular arrhythmias. It is crucial to evaluate electrolyte levels and medication history when interpreting these changes.
Additionally, the presence of U waves may suggest hypokalemia or other electrolyte imbalances, further emphasizing the importance of a comprehensive analysis of the patient's clinical status and laboratory results.
In summary, a thorough evaluation of the EKG should include careful consideration of T wave morphology, QT interval duration, and the presence of U waves, as these findings can provide critical insights into the patient's cardiac health and potential underlying conditions.